1. Field of the Invention
The present invention relates to a method for distinguishing activated natural killer cells from resting, non-activated killer cells.
2. Description of the Prior Art
Considerable attention has recently been given to the study of cells from unimmunized hosts which are capable of lysing tumor cells in vitro. Such cells are commonly referred to as natural killer cells. Natural killer cells may play an important role in malignancy and disease. Essentially all natural killer cells present in human peripheral blood can be identified using the commercially available anti-Leu 11 monoclonal antibody. It is known that the use of certain cancer treatment agents, such as interferon, interferon-inducing agents, and interleukins, influence the number and potency of natural killer cells in human peripheral blood. Any process of influencing the number and potency of natural killer cells is referred to herein as "activation" of natural killer cells. These natural killer cells are referred to as "activated natural killer cells". Activated natural killer cells differ in functional properties from unactivated, resting natural killer cells. Human natural killer cells are known to express a variety of antigens, some of which are common to the T cell lineage and others to the myeloid cell lineage. Activated natural killer cells have increased levels of expression of certain cell surface antigens, such as DR, DS, and transferrin receptor.
It whould be desirable to provide a method whereby activated natural killer cells can be distinguished and enumerated separately from resting, non-activated natural killer cells, to permit monitoring of changes which may occur in natural killer cell populations during the development and treatment of disease.